Endocrine Abstracts

The prevalence of obesity is increasing in most populations. The aim of this study was to provide baseline data on the concentrations of chlorinated and brominated dioxins and related compounds as well as polybrominated diphenyl ethers to assess whether concentrations of these compounds are higher in obese than control subjects.

Materials and Methods: Patients undergoing Roux-en-y gastric bypass surgery for weight loss and control patients who were undergoing abdominal surgery for non-bariatric reasons were recruited with informed consent for the study. Anthropometric parameters were measured at the day of surgery. During surgery, visceral and subcutaneous adipose tissue biopsies, liver biopsy and blood samples were taken.

Results: Patients undergoing bariatric surgery were younger on average than control patients (47.9 (12.7) vs 68.5 (14.2) years) and on average had higher BMI. Tissue concentrations were measured in samples of visceral and subcutaneous fat and in liver biopsies. Brominated TEQ concentrations were relatively low compared to chlorinated TEQ, constituting less than 5% of adipose tissue TEQ and less than 10% of liver TEQ. The most frequently detected PBDD/F compounds were 2,3,7,8-tetrabromodibenzodioxin, 2,3,7,8-tetrabromodibenzofuran, and 2,3,4,7,8-pentabromodibenzofuran. The PBDE compounds presented here are those that were consistently detected in the samples. Of these, BDE 153 was present at the highest concentrations, followed by BDE 47.

Multivariate linear regressions showed chlorinated TEQ in visceral fat was significantly positively associated with both age and BMI. In contrast, brominated TEQ compounds showed no significant association with any of the factors considered. BDE 47 was borderline significantly negatively associated with age, while BDE 153 showed a borderline significant negative relationship to BMI. Gender was not a significant factor for any analyte.

Conclusion: Subcutaneous fat concentrations were highly correlated with visceral fat concentrations for all analytes. This confirms that concentrations of these compounds in fat depots in the body appear to be generally in equilibrium, an observation previously made for chlorinated TEQ compounds but not previously demonstrated in humans for PBDD/Fs and PBDEs.